What is an alternative to INCOLOY 825?
Incoloy 825 vs Inconel 625
Inconel is a nickel-based high-temperature alloy. Depending on the amount of nickel in the alloy, and taking into account many other parameters, we can grade Inconel differently. Two such grades are Inconel 625 and Incoloy 825. The main difference between the two is that Inconel 625 contains a high amount of nickel compared to Incoloy 825.
What is Inconel 625?
Inconel 625 contains more nickel than other grades of Inconel and it is a nickel-based high-temperature alloy. It has high strength and high resistivity at higher temperatures. It has very good protection against corrosion and oxidation. These particular advantages make it very useful in nuclear and marine applications.
The service temperature range of Inconel 625 alloy starts from cryogenic temperatures up to 982°C. The high strength of this alloy is due to the hardening effect of niobium and molybdenum in the nickel-chromium matrix. Therefore, precipitation hardening treatment is not required for Inconel alloy. Inconel 625 is an excellent choice for seawater applications due to its high tensile strength, high corrosion fatigue strength and resistance to chloride stress corrosion cracking. In addition to this, it exhibits excellent toughness and ductility at cryogenic temperatures.
Inconel Alloy 625 Chemical Composition
Inconel Elements (mass %)
Ni Cr Fe Mo Nb Co Mn Cu Al Ti Si C S P B
625 58.0 20.0–23.0 5.0 8.0–10.0 3.15–4.15 1.0 0.5 0.4 0.4 0.5 0.1 0.015 0.015
Alloy 625 Equivalent Materials
Standard WERKSTOFF NR. UNS GOST AFNOR JIS BS EN OR
Inconel 625 2.4856 N06625 ХН75МБТЮ NC22DNB4M NCF 625 NA 21 NiCr22Mo9Nb ЭИ602
Inconel 625 Mechanical Properties
Density Melting Point Tensile Strength Yield Strength (0.2% Shift) Elongation
625 8.4 g/cm3 1350 °C (2460 °F) Psi – 135,000 , MPa – 930 Psi – 75,000 , MPa – 517 42.5 %
What is Incoloy 825?
Compared to other Inconel grades, Incoloy 825 contains a moderate amount of nickel and is a nickel-based superalloy. It has a high melting point but low yield strength and tensile strength. It contains chromium and nickel along with titanium, molybdenum and copper. It provides excellent corrosion resistance especially to aqueous corrosion. Apart from this, it also exhibits resistance to oxidizing and reducing acids such as phosphoric acid and sulfuric acid.
Difference between Inconel 625 and Incoloy 825
| Inconel 625 | Incoloy 825 | |
| Defination | It is nickel based superalloy which contains a high amount of nickel than any other grade of Inconel | It is nickel based superalloy which contains a moderate amount of nickel as compared to any other grade of Inconel |
| Nickel Content | It contains about 58% of nickel | It contains about 36-48% of nickel |
| Tensile Strength | It has very high tensile strength and yield strength | It has comparatively low tensile strength and yield strength |
| Elongation | It's elongation is about 42.52% | It's elongation is about 30% |
Incoloy 825 Material Composition
| Alloy | Ni | Cr | Fe | Mb | Ti | Cu | Mn | C | S | Al | Si |
| Incoloy 825 | 38.0 – 46.0 | 19.5 – 23.5 | 22.0 min | 2.5 – 3.5 | 0.6 – 1.2 | 1.5 – 3.0 | 1.0 max | 0.05 max | 0.03 max | 0.2 max | 0.5 max |
Alloy 825 Equivalent Material
| ALLOY | WERKSTOFF NR. | UNS | GOST | AFNOR | JIS | BS | EN | OR |
| Incoloy 825 | 2.4858 | N08825 | ЭП703 | NFE30C20DUM | NCF 825 | NA 16 | NiCr21Mo | XH38BT |
